A can of sardines is made to move along an x axis from x1 = 0.2 m to x2 = 1.2 m by a force given by F = iF0exp(-0.4x), with x in meters and F0 = 4.5 N. (Here exp is the exponential function.) How much work is done on the can by the force?

This, however, is the wrong answer. Did I do something wrong in my calculations???

Significant figures: the least precise x is in ONE significant figure. Geez. The most precise is two sif figures. You have the problem set up correctly.
I don't get the same final value as you, we are different by approximately a factor of ten.